Mobile device and optical imaging lens thereof

ABSTRACT

Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises four lens elements positioned in an order from the object side to the image side. Through controlling the convex or concave shape of the surfaces of the lens elements, the thickness of the at least one lens element, an air gap between two lens elements, and a sum of all air gaps between all four lens elements along the optical axis satisfying the relations: (T3/G 34 )&gt;4 and (G aa /T3)&gt;1, wherein T3 is the thickness of the third lens element, G 34  is the air gap between the third lens element and the fourth lens element, and G aa  is the sum of all air gaps between all four lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

INCORPORATION BY REFERENCE

This application claims priority from China Patent Application No.201210252531.0, filed on Jul. 20, 2012, the contents of which are herebyincorporated by reference in their entirety for all purposes.

TECHNICAL FIELD

The present invention relates to a mobile device and an optical imaginglens thereof, and particularly, relates to a mobile device applying anoptical imaging lens having four lens elements and an optical imaginglens thereof.

BACKGROUND

The ever-increasing demand for smaller sized mobile devices, such ascell phones, digital cameras, etc. has correspondingly triggered agrowing need for smaller sized photography modules contained therein.Size reductions may be contributed from various aspects of the mobiledevices, which includes not only the charge coupled device (CCD) and thecomplementary metal-oxide semiconductor (CMOS), but also the opticalimaging lens mounted therein. When reducing the size of the opticalimaging lens; however, achieving good optical characteristics becomes achallenging problem.

U.S. Pat. No. 7,715,119, U.S. Pat. No. 7,848,032, U.S. Pat. No.8,089,704, U.S. Pat. No. 7,920,340, US Patent Publication No.20110090572, U.S. Pat. No. 7,777,972, U.S. Pat. No. 7,969,664 and U.S.Pat. No. 7,274,518 all disclosed an optical imaging lens constructedwith an optical imaging lens having four lens elements. In the firstembodiment of U.S. Pat. No. 7,920,340, the length of the optical imaginglens is over 7 mm, which is not beneficial for the smaller design ofmobile devices.

How to effectively shorten the length of the optical imaging lens is oneof the most important topics in the industry to pursue the trend ofsmaller and smaller mobile devices. Therefore, there is needed todevelop optical imaging lens with a shorter length, while also havinggood optical characters.

SUMMARY

An object of the present invention is to provide a mobile device and anoptical imaging lens thereof. With controlling the convex or concaveshape of the surfaces of the lens elements, the central thickness alongthe optical axis, and the air gap, etc., the length of the opticalimaging lens is shortened and meanwhile the good optical characters,such as high resolution, are sustained.

In an exemplary embodiment, an optical imaging lens comprises, in orderfrom an object side to an image side, first, second, third and fourthlens elements, each of the first, second, third, and fourth lenselements having an object-side surface facing toward the object side andan image-side surface facing toward the image side. The first lenselement has positive refracting power and the object-side surfacethereof is a convex surface. The second lens element has negativerefracting power, the object-side surface thereof comprises a concaveportion in the vicinity of the optical axis and the image-side surfacethereof comprises a concave portion in the vicinity of the optical axis.The third lens element has positive refracting power, the object-sidesurface thereof is a concave surface and the image-side surface thereofbeing a convex surface. The object-side surface of the fourth lenselement comprises a convex portion in the vicinity of the optical axis,and the image-side surface thereof comprises a concave portion in thevicinity of the optical axis and a convex portion in the vicinity of aperiphery of the fourth lens element. Lens as a whole has only the fourlens elements with refracting power, wherein a central thickness of thethird lens element along the optical axis is T3, an air gap between thethird lens element and the fourth lens element is G₃₄, and a sum of allair gaps from the first lens element to the fourth lens element alongthe optical axis is G_(aa), and they satisfy the relations:

(T3/G ₃₄)>4; and

(G _(aa) /T3)>1.

In another exemplary embodiment, assuming the thickness of the thirdlens element is not changed, when the air gap G₃₄ between the third lenselement and the fourth lens element along the optical axis is shortenedto satisfy the relation of “(T3/G₃₄)>4”, the length of the opticalimaging lens is shortened. In another exemplary embodiment, assuming thesum of all air gaps from the first lens element to the fourth lenselement along the optical axis, G_(aa), is not changed, when the centralthickness T3 of the third lens element along the optical axis isshortened to satisfy the relation of “(G_(aa)/T3)>1”, the length of theoptical imaging lens is also effectively shortened.

In another exemplary embodiment, other related parameters, such as thecentral thickness of lens element along the optical axis and other ratioof the central thickness of lens element along the optical axis to thesum of all air gaps, focal length, and/or other related parameters couldbe further controlled. For example, these related parameters could be acentral thickness of the second lens element along the optical axis, T2,an air gap between the first lens element and the second lens element,G₁₂, an effective focal length, EFL, of the optical imaging lens, a backfocal length, BFL, of the optical imaging lens, a focal length of thefirst lens element, f1, and a focal length of the third lens element,f3, satisfying at least one of the relations:

(EFL/G ₁₂)<24;

(T3/G₁₂)<5;

0.5≦(T2+T3)≦0.83 (mm);

1.5<[(T2+T3)/T3]<2.5;

0.07<(G ₁₂ +G ₃₄)<0.25 (mm);

2<(f1+f3)<4 (mm); and/or

(BFL/EFL)≧0.5,

wherein, BFL is defined by the distance between the image-side surfaceof the fourth lens element and an image plane along the optical axis.

Aforesaid exemplary embodiments are not limited and could be selectivelyincorporated in other embodiments described herein.

In example embodiments, an aperture stop is provided for adjusting theinput of light of the system. For example, the aperture stop ispreferably provided but not limited to be positioned in front of thefirst lens element, or positioned between the first lens element and thesecond lens element.

In some exemplary embodiments, more details about the convex or concavesurface structure and/or the refracting power could be incorporated forone specific lens element or broadly for plural lens elements to enhancethe control for the system performance and/or resolution. For example,for the first lens element, an image-side surface is comprised, but theimage-side surface need not be limited to a convex portion in thevicinity of a periphery of the first lens element.

In another exemplary embodiment, a mobile device comprises a housing andan optical imaging lens assembly positioned in the housing. The opticalimaging lens assembly comprises a lens barrel, any of aforesaid exampleembodiments of optical imaging lens, a module housing unit, and an imagesensor. The lens comprising four lens elements with refracting power asa whole is positioned in the lens barrel, the module housing unit is forpositioning the lens barrel, and the image sensor is positioned at theimage-side of the optical imaging lens.

In some exemplary embodiments, the module housing unit optionallycomprises an autofocus module and/or an image sensor base. The autofocusmodule may comprise a lens seat and a lens backseat, wherein the lensseat is positioned close to the outside of the lens barrel along with anaxis; the lens backseat is positioned along the axis and around theoutside of the lens seat; and the lens barrel and the optical imaginglens positioned therein are driven by the lens seat for moving along theaxis to control the focusing of the optical imaging lens. The imagesensor base could be positioned between the lens backseat and the imagesensor, and closed to the lens backseat.

Through controlling the ratio among at least one central thickness oflens element along the optical axis, an air gap between two lenselements along the optical axis, and a sum of all air gaps between thefour lens elements along the optical axis in a predetermined range, andincorporated with the arrangement of the convex or concave shape of thesurfaces of the lens element(s) and/or refraction power, the mobiledevice and the optical imaging lens thereof in exemplary embodimentsachieve good optical characters and effectively shorten the length ofthe optical imaging lens.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be more readily understood from the followingdetailed description when read in conjunction with the appended drawing,in which:

FIG. 1 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 1of the invention;

FIG. 2 shows a table of optical data of each lens element of the opticalimaging lens according to embodiment 1 of the invention;

FIG. 3 shows another cross-sectional view of a lens element of theoptical imaging lens according to embodiment 1 of the invention;

FIG. 4 shows a table of aspherical data of the optical imaging lensaccording to embodiment 1 of the invention;

FIG. 5 shows charts of longitudinal spherical aberration and other kindsof optical aberrations of the optical imaging lens according toembodiment 1 of the invention;

FIG. 6 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 2of the invention;

FIG. 7 shows a table of optical data of each lens element of the opticalimaging lens according to embodiment 2 of the invention;

FIG. 8 shows a table of aspherical data of the optical imaging lensaccording to embodiment 2 of the invention;

FIG. 9 shows charts of longitudinal spherical aberration and other kindsof optical aberrations of the optical imaging lens according toembodiment 2 of the invention;

FIG. 10 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 3of the invention;

FIG. 11 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 3 of the invention;

FIG. 12 shows a table of aspherical data of the optical imaging lensaccording to embodiment 3 of the invention;

FIG. 13 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 3 of the invention;

FIG. 14 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 4of the invention;

FIG. 15 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 4 of the invention;

FIG. 16 shows a table of aspherical data of the optical imaging lensaccording to embodiment 4 of the invention;

FIG. 17 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 4 of the invention;

FIG. 18 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 5of the invention;

FIG. 19 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 5 of the invention;

FIG. 20 shows a table of aspherical data of the optical imaging lensaccording to embodiment 5 of the invention;

FIG. 21 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 5 of the invention;

FIG. 22 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 6of the invention;

FIG. 23 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 6 of the invention;

FIG. 24 shows a table of aspherical data of the optical imaging lensaccording to embodiment 6 of the invention;

FIG. 25 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 6 of the invention;

FIG. 26 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 7of the invention;

FIG. 27 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 7 of the invention;

FIG. 28 shows a table of aspherical data of the optical imaging lensaccording to embodiment 7 of the invention;

FIG. 29 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 7 of the invention;

FIG. 30 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 8of the invention;

FIG. 31 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 8 of the invention;

FIG. 32 shows a table of aspherical data of the optical imaging lensaccording to embodiment 8 of the invention;

FIG. 33 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 8 of the invention;

FIG. 34 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment 9of the invention;

FIG. 35 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 9 of the invention;

FIG. 36 shows a table of aspherical data of the optical imaging lensaccording to embodiment 9 of the invention;

FIG. 37 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 9 of the invention;

FIG. 38 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment10 of the invention;

FIG. 39 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 10 of the invention;

FIG. 40 shows a table of aspherical data of the optical imaging lensaccording to embodiment 10 of the invention;

FIG. 41 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 10 of the invention;

FIG. 42 shows a cross-sectional view of an optical imaging lens havingfour lens elements of the optical imaging lens according to embodiment11 of the invention;

FIG. 43 shows a table of optical data of each lens element of theoptical imaging lens according to embodiment 11 of the invention;

FIG. 44 shows a table of aspherical data of the optical imaging lensaccording to embodiment 11 of the invention;

FIG. 45 shows charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according toembodiment 11 of the invention;

FIG. 46 shows a comparison table for the values of T3/G₃₄, G_(aa)/T3,EFL/G₁₂, T3/G₁₂, T2+T3, (T2+T3)/T3, G₁₂+G₃₄, f1+f3, and BFL/EFL of all11 example embodiments shown in FIGS. 1-45;

FIG. 47 shows a structure of an example embodiment of a mobile device;

FIG. 48 shows an partially enlarged view of a structure of anotherexample embodiment of a mobile device.

DETAILED DESCRIPTION

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumbers indicate like features. Persons having ordinary skill in the artwill understand other varieties for implementing example embodiments,including those described herein. The drawings are not limited tospecific scale and similar reference numbers are used for representingsimilar elements. As used in the disclosures and the appended claims,the terms “example embodiment,” “exemplary embodiment,” and “presentembodiment” do not necessarily refer to a single embodiment, although itmay, and various example embodiments may be readily combined andinterchanged, without departing from the scope or spirit of the presentinvention. Furthermore, the terminology as used herein is for thepurpose of describing example embodiments only and is not intended to bea limitation of the invention. In this respect, as used herein, the term“in” may include “in” and “on”, and the terms “a”, “an” and “the” mayinclude singular and plural references. Furthermore, as used herein, theterm “by” may also mean “from”, depending on the context. Furthermore,as used herein, the term “if” may also mean “when” or “upon”, dependingon the context. Furthermore, as used herein, the words “and/or” mayrefer to and encompass any and all possible combinations of one or moreof the associated listed items.

Example embodiments of an optical imaging lens may comprise a first lenselement, a second lens element, a third lens element, and a fourth lenselement. These lens elements may be arranged in an order from an objectside to an image side, and example embodiments of the lens as a wholemay comprise only the four lens elements with refracting power. In anexample embodiment: the first lens element has positive refracting powerand the object-side surface thereof is a convex surface; the second lenselement has negative refracting power, the object-side surface thereofcomprises a concave portion in the vicinity of the optical axis and theimage-side surface thereof comprises a concave portion in the vicinityof the optical axis; the third lens element has positive refractingpower, the object-side surface thereof is a concave surface and theimage-side surface thereof being a convex surface; the object-sidesurface of the fourth lens element comprises a convex portion in thevicinity of the optical axis, and the image-side surface thereofcomprises a concave portion in the vicinity of the optical axis and aconvex portion in the vicinity of a periphery of the fourth lenselement. The central thickness of the third lens element along theoptical axis, T3, an air gap between the third lens element and thefourth lens element, G₃₄, and the sum of all air gaps between the firstlens element to the fourth lens element along the optical axis, G_(aa),satisfy the relations as followed:

(T3/G ₃₄)>4   relation (1); and

(G _(aa) /T3)>1   relation (2).

Preferably, the first lens element having positive refracting power havebetter light converge ability and the third lens element and the fourthlens element could eliminate the astigmatism aberration and distortionaberration to reduce the aberration of the whole system to achieve goodoptical characters and shortened the length of the optical imaging lens.

Reference is now made to relation (1). A person having ordinary skill inthe art would readily understand that when the air gap G₃₄ between thethird lens element and the fourth lens element along the optical axis isshortened to satisfy relation (1), assuming the thickness of the thirdlens element is not changed, the length of the optical imaging lenswould be shortened. If relation (1) is not satisfied, i.e. (T3/G₃₄)<4,the air gap between the third lens element and the fourth lens elementmay be large that it would cause a long optical imaging lens. Relation(1) may be further restricted by an upper limit, for example but notlimited to, 15>(T3/G₃₄)>4.

Reference is now made to relation (2). A person having ordinary skill inthe art would readily understand that when the central thickness T3 ofthe third lens element along the optical axis is shortened to satisfyrelation (2), assuming the sum of all air gaps from the first lenselement to the fourth lens element along the optical axis, G_(aa), isnot changed, the length of the optical imaging lens would also beeffectively shortened. If relation (2) is not satisfied, i.e.(G_(aa)/T3)<1, the thickness of the third lens along the optical axismay be so large that it would cause a long optical imaging lens.Relation (2) may be further restricted by an upper limit, for examplebut not limited to, 2>(G_(aa)/T3)>1. By applying these techniques, thelength of the optical imaging lens can be shortened.

In some example embodiments, other related parameters, such as thecentral thickness of lens element along the optical axis, focal length,and/or other related parameters could be further controlled. Forexample, these related parameters could be a central thickness of thesecond lens element along the optical axis, T2, an air gap between thefirst lens element and the second lens element, G₁₂, an effective focallength, EFL, of the optical imaging lens, a back focal length, BFL, ofthe optical imaging lens, a focal length of the first lens element, f1,and a focal length of the third lens element, f3, satisfying at leastone of the relations:

(EFL/G ₁₂)<24   relation (3);

(T3/G ₁₂)<5   relation (4);

0.5≦(T2+T3)≦0.83 (mm)   relation (5);

1.5<[(T2+T3)/T3]<2.5   relation (6);

0.07<(G ₁₂ +G ₃₄)<0.25 (mm)   relation (7);

2<(f1+f3)<4 (mm)   relation (8); and/or

(BFL/EFL)≧0.5   relation (9),

wherein, BFL is defined by the distance between the image-side surfaceof the fourth lens element and an image plane along the optical axis.

Reference is now made to relation (3). A person having ordinary skill inthe art would readily understand that when relation (3) is satisfied,assuming the air gap G₁₂ between the first lens element and the secondlens element along the optical axis is not shortened, the effectivefocal length of the optical imaging lens would be shorter to effectivelyshorten the length of the optical imaging lens. If relation (3) is notsatisfied, i.e. (EFL/G₁₂)>24, the effective focal length of the opticalimaging lens is so long that a long optical imaging lens is caused.Relation (3) may be further restricted by a lower limit. For example, alower limit may be, but is not limited to, 17<(EFL/G₁₂)<24.

Reference is now made to relation (4). A person having ordinary skill inthe art would readily understand that if relation (4) is not satisfied,i.e. (T3/G₁₂)>5, the central thickness of the third lens element alongthe optical axis is so thick that a long optical imaging lens is caused.Relation (4) may be further restricted by a lower limit. For example, alower limit may be, but is not limited to, 2<(T3/G₁₂)<5.

Reference is now made to relation (5). A person having ordinary skill inthe art would readily understand the results if relation (5) is notsatisfied. If the lower limit is exceeded, i.e. (T2+T3)<0.5 (mm), thecentral thickness of the second lens element or third lens element alongthe optical axis would be so thin that making the optical imaging lenswould be difficult. If the upper limit is exceeded, i.e. 0.83≦(T2+T3)(mm), the central thickness of the second lens element or the third lenselement along the optical axis would be so thick as to cause a longoptical imaging lens.

Reference is now made to relation (6). A person having ordinary skill inthe art would readily understand the results if relation (6) is notsatisfied. If the lower limit is exceeded, i.e. [(T2+T3)/T3]<1.5, thecentral thickness of the third lens element along the optical axis wouldbe so thick as to cause a long optical imaging lens. If the upper limitis exceeded, i.e. [(T2+T3)/T3]>2.5, assuming the thickness of the thirdlens element is not changed, the central thickness of the second lenselement along the optical axis would be so thick as to cause a longoptical imaging lens.

Reference is now made to relation (7). A person having ordinary skill inthe art would readily understand the results if relation (7) is notsatisfied. If the lower limit is exceeded, i.e. (G₁₂+G₃₄)≦0.07 (mm), theair gap between the first lens element and the second lens element orthe air gap between the third lens element and the fourth lens elementalong the optical axis would be so narrow that manufacturing the opticalimaging lens would be difficult. If the upper limit is exceeded, i.e.(G₁₂+G₃₄)>0.25 (mm), the sum of the air gap between the first lenselement and the second lens element and the air gap between the thirdlens element and the fourth lens element along the optical axis is solarge that a long optical imaging lens is caused.

Reference is now made to relation (8). A person having ordinary skill inthe art would readily understand the results if relation (8) is notsatisfied. If the lower limit is exceeded, i.e. (f1+f3)<2 (mm), thefocal length of the first lens element or the third lens element wouldbe short and the refracting power of the first lens element or the thirdlens element would be large. Arrangement of the refracting power forsuch a system is difficult. If the upper limit is exceeded, i.e.(f1+f3)>4 (mm), the focal length of the first lens element or third lenselement would be so long as to cause a long optical imaging lens.

Reference is now made to relation (9). A person of ordinary skill in theart would readily understands that when relation (9) is satisfied, theeffective focal length of the optical imaging lens would be shorter. Ifrelation (9) is not satisfied, i.e. (BFL/EFL)<0.5, the effective focallength of the optical imaging lens would be so long as to cause a longoptical imaging lens.

When implementing example embodiments, more details about the convex orconcave surface structure and/or the refracting power may beincorporated for one specific lens element or broadly for plural lenselements to enhance the control for the system performance and/orresolution, as illustrated in the following embodiments. It is notedthat the details listed here could be incorporated in exampleembodiments if no inconsistency occurs.

Several exemplary embodiments and associated optical data will now beprovided for illustrating example embodiments of optical imaging lenswith good optical characters and a shortened length. Reference is nowmade to FIGS. 1-5. FIG. 1 illustrates an example cross-sectional view ofan optical imaging lens having four lens elements of the optical imaginglens according to a first example embodiment. FIG. 2 illustrates anexample table of optical data of each lens element of the opticalimaging lens according to an example embodiment. FIG. 3 depicts anotherexample cross-sectional view of a lens element of the optical imaginglens according to an example embodiment. FIG. 4 depicts an example tableof aspherical data of the optical imaging lens according to an exampleembodiment. FIG. 5 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens according to an example embodiment.

As shown in FIG. 1, the optical imaging lens 1 of the present embodimentcomprises, in order from an object side A1 to an image side A2, anaperture stop 100, a first lens element 110, a second lens element 120,a third lens element 130 and a fourth lens element 140. Both of afiltering unit 150 and an image plane 160 of an image sensor arepositioned at the image side A2 of the optical imaging lens 1. Each ofthe first, second, third, fourth lens elements 110, 120, 130, 140 andthe filtering unit 150 has an object-side surface 111/121/131/141/151facing toward the object side A1 and an image-side surface112/122/132/142/152 facing toward the image side A2. The aperture stop100, positioned in front of the first lens element 110, and togetherwith the first lens element 110 having positive refracting power couldeffectively shorten the length of the optical imaging lens 1. Theexample embodiment of the filtering unit 150 illustrated is an IR cutfilter (infrared cut filter) positioned between the fourth lens element140 and an image plane 160. The filtering unit 150 filters light withspecific wavelength from the light passing optical imaging lens. Forexample, IR light is filtered, and this will prohibit the IR light whichis not seen by human eyes from producing an image on the image plane160.

Exemplary embodiments of each lens elements of the optical imaging lens1 will now be described with reference to the drawings.

The first lens element 110 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 111 andthe image-side surface 112 are convex surfaces. The convex surface 111and convex surface 112 may both be aspherical surfaces.

The second lens element 120 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 121and the image-side surface 122 are concave surfaces. The concave surface121 and concave surface 122 may both be aspherical surfaces.

The third lens element 130 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 131 is aconcave surface and the image-side surface 132 is a convex surface. Theconcave surface 131 and the convex surface 132 may both be asphericalsurfaces.

The fourth lens element 140 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 141comprises a convex portion 1411 in the vicinity of the optical axis anda concave portion 1412 in the vicinity of the periphery of the fourthlens element 140. The image-side surface 142 has a concave portion 1421in the vicinity of the optical axis and a convex portion 1422 in thevicinity of a periphery of the fourth lens element 140. The object-sidesurface 141 and the image-side surface 142 may both be asphericalsurfaces.

In example embodiments, air gaps exist between the four lens elements110, 120, 130, 140, the filtering unit 150 and the image plane 160 ofthe image sensor. For example, FIG. 1 illustrates the air gap d1existing between the first lens element 110 and the second lens element120, the air gap d2 existing between the second lens element 120 and thethird lens element 130, the air gaps d existing between the third lenselement 130 and the fourth lens element 140, the air gap d4 existingbetween the fourth lens element 140 and the filtering unit 150 and theair gap d5 existing between the filtering unit 150 and the image plane160 of the image sensor. However, in other embodiments, any of theaforesaid air gaps may or may not exist. For example, the profiles ofopposite surfaces of any two adjacent lens elements may correspond toeach other, and in such situation, the air gaps may not exist. The airgap d1 is denoted by G₁₂, the air gap d3 is denoted by G₃₄, and the sumof all air gaps d1, d2, d3 between the first and fourth lens elements isdenoted by G_(aa).

FIG. 2 depicts the optical characters of each lens elements in theoptical imaging lens 1 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=11.45;

(G _(aa) /T3)=1.21;

(EFL/G ₁₂)=23.87;

(T3/G ₁₂)=4.06;

(T2+T3)=0.69 (mm);

[(T2+T3)/T3]=1.73;

(G ₁₂ +G ₃₄)=0.13 (mm);

(f1+f3)=3.21 (mm);

(BFL/EFL)=0.5;

wherein the distance from the object-side surface 111 of the first lenselement 110 to the image plane 160 is 3.063 (mm), and the length of theoptical imaging lens is shortened.

Please note that, in example embodiments, to clearly illustrate thestructure of each lens element, only the part where light passes, isshown. For example, taking the first lens element 110 as an example,FIG. 1 illustrates the object-side surface 111 and the image-sidesurface 112. However, when implementing each lens element 110, 120, 130,140 of the present embodiment, a fixing part for positioning the lenselements inside the optical imaging lens may be formed selectively.Based on the first lens element 110, please refer to FIG. 3, whichillustrates the first lens element 110 further comprising a fixing part.Here the fixing part is not limited to a protruding part 113 formounting the first lens element 110 in the optical imaging lens, andideally, light will not pass through the protruding part 113.

The aspherical surfaces, including the convex surface 111 and the convexsurface 112 of the first lens element 110, the concave surfaces 121, 122of the second lens element 120, the concave surface 131 and the convexsurface 132 of the third lens element 130, and the object-side surface141 and the image-side surface 142 of the fourth lens element 140 areall defined by the following aspherical formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}\; {a_{2\; i} \times Y^{2\; i}}}}$

wherein:

R represents the radius of the surface of the lens element;

Z represents the depth of the aspherical surface (the perpendiculardistance between the point of the aspherical surface at a distance Yfrom the optical axis and the tangent plane of the vertex on the opticalaxis of the aspherical surface);

Y represents the perpendicular distance between the point of theaspherical surface and the optical axis;

K represents a conic constant;

a_(2i) represents a aspherical coefficient of 2i^(th) level;

and the values of each aspherical parameter are represented in FIG. 4.

As illustrated in FIG. 5, the optical imaging lens of present exampleembodiments show great optical characteristics in the longitudinalspherical aberration (a), astigmatism aberration in the sagittaldirection (b), astigmatism aberration in the tangential direction (c)and distortion aberration (d). Therefore, according to aboveillustration, the optical imaging lens of example embodiments indeedachieve great optical performance and the length of the optical imaginglens is effectively shortened.

Reference is now made to FIGS. 6-9. FIG. 6 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a second exampleembodiment. FIG. 7 shows an example table of optical data of each lenselement of the optical imaging lens according to the second exampleembodiment. FIG. 8 shows an example table of aspherical data of theoptical imaging lens according to the second example embodiment. FIG. 9shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according to anexample embodiment.

As shown in FIG. 6, the optical imaging lens 2 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 200, a first lens element 210, a second lenselement 220, a third lens element 230 and a fourth lens element 240. Theaperture stop 200, positioned in front of the first lens element 210,and together with the first lens element 210 having positive refractingpower could effectively shorten the length of the optical imaging lens2. Both of a filtering unit 250 and an image plane 260 of an imagesensor are positioned at the image side A2 of the optical imaging lens2. Each of the first, second, third, fourth lens elements 210, 220, 230,240 and the filtering unit 250 has an object-side surface211/221/231/241/251 facing toward the object side A1 and an image-sidesurface 212/222/232/242/252 facing toward the image side A2. In anexample embodiment, the filtering unit 250 is an IR cut filterpositioned between the fourth lens element 240 and the image plane 260.The filtering unit 250 filters light with specific wavelength from thelight passing optical imaging lens 2. For example, IR light is filtered,and this will prohibit the IR light which is not seen by human eyes fromproducing an image on image plane 260.

Similarly, in the present embodiment, air gaps exist between the lenselements 210, 220, 230, 240, the filtering unit 250 and the image plane260 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the second embodiments and the first embodimentsis that the central thickness of lens T3 of the third lens element 230,the air gap G₃₄ between the third lens element 230 and the fourth lenselement 240 and the sum of all air gaps G_(aa) from the first lenselement 210 to the fourth lens element 240 are different. Please referto FIG. 7 for the optical characteristics of each lens elements in theoptical imaging lens 2 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=7.01;

(G _(aa) /T3)=1.26;

(EFL/G ₁₂)=23.80;

(T3/G ₁₂)=3.84;

(T2+T3)=0.73 (mm);

[(T2+T3)/T3]=1.77;

(G ₁₂ +G ₃₄)=0.17 (mm);

(f1+f3)=3.23 (mm);

(BFL/EFL)=0.51;

wherein the distance from the object-side surface 211 of the first lenselement 210 to the image side of the image plane 260 is 3.266 (mm) andthe length of the optical imaging lens 2 is shortened.

Example embodiments of the lens elements of the optical imaging lens 2may comprise the following example embodiments:

The first lens element 210 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 211 andthe image-side surface 212 are convex surfaces. The convex surface 211and convex surface 212 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 8 for values of the asphericalparameters.

The second lens element 220 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 221and the image-side surface 222 are concave surfaces. The concavesurfaces 221, 222 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 8 for values of the asphericalparameters.

The third lens element 230 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 231 is aconcave surface and the image-side surface 232 is a convex surface. Theconcave surface 231 and the convex surface 232 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 8 forvalues of the aspherical parameters.

The fourth lens element 240 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 241 is aconvex surface. The image-side surface 242 has a concave portion 2421 inthe vicinity of the optical axis and a convex portion 2422 in thevicinity of a periphery of the fourth lens element 240. The convexsurface 241 and the image-side surface 242 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 8 forvalues of the aspherical parameters.

As shown in FIG. 9, the optical imaging lens 2 of the present embodimentshows great optical characteristics in longitudinal spherical aberration(a), astigmatism in the sagittal direction (b), astigmatism in thetangential direction (c) and distortion aberration (d). Therefore,according to the above illustration, the optical imaging lens of thepresent embodiment indeed shows great optical performance and the lengthof the optical imaging lens is effectively shortened.

Reference is now made to FIGS. 10-13. FIG.10 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a third exampleembodiment. FIG. 11 depicts an example table of optical data of eachlens element of the optical imaging lens according to the third exampleembodiment. FIG. 12 depicts an example table of aspherical data of theoptical imaging lens according to the third example embodiment. FIG. 13shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe third example embodiment.

As shown in FIG. 10, the optical imaging lens 3 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 300, a first lens element 310, a second lenselement 320, a third lens element 330 and a fourth lens element 340.Both of a filtering unit 350 and an image plane 360 of an image sensormay be positioned at the image side A2 of the optical imaging lens 3.Each of the first, second, third, fourth lens elements 310, 320, 330,340 and the filtering unit 350 has an object-side surface311/321/331/341/351 facing toward the object side A1 and an image-sidesurface 312/322/332/342/352 facing toward the image side A2. Theaperture stop 300, positioned in front of the first lens element 310,and together with the first lens element 310 having positive refractingpower could effectively shorten the length of the optical imaging lens3. Here an example embodiment of the filtering unit 350 is an IR cutfilter positioned between the fourth lens element 340 and the imageplane 360. The filtering unit 350 filters light with specific wavelengthfrom the light passing optical imaging lens. For example, the IR lightis filtered, and this will prohibit the IR light which is not seen byhuman eyes from producing an image on image plane 360.

Similarly, in the present embodiment, air gaps exist between the lenselements 310, 320, 330, 340, the filtering unit 350 and the image plane360 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the third embodiment and the first embodiment isthat the central thickness of lens T3 of the third lens element 330, theair gap G₃₄ between the third lens element 330 and the fourth lenselement 340 and the sum of all air gaps G_(aa) from the first lenselement 310 to the fourth lens element 340 are different. Please referto FIG. 11 for the optical characteristics of each lens elements in theoptical imaging lens 3 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=4.90;

(G _(aa) /T3)=1.46;

(EFL/G ₁₂)=18.69;

(T3/G ₁₂)=2.88;

(T2+T3)=0.73 (mm);

[(T2+T3)/T3]=1.91;

(G ₁₂ +G ₃₄)=0.21 (mm);

(f1+f3)=3.21 (mm);

(BFL/EFL)=0.48;

wherein the distance from the object-side surface 311 of the first lenselement 310 to the image side of the image plane 360 is 3.158 (mm), andthe length of the optical imaging lens 3 is shortened.

Example embodiments of the lens elements 3 of the optical imaging lensmay comprise the following example embodiments:

The first lens element 310 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 311 andthe image-side surface 312 are convex surfaces. The convex surfaces 311,312 may both be aspherical surfaces defined by the aspherical formula.Please refer to FIG. 12 for values of the aspherical parameters.

The second lens element 320 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 321and the image-side surface 322 are concave surfaces. The concavesurfaces 321, 322 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 12 for values of the asphericalparameters.

The third lens element 330 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 331 is aconcave surface and the image-side surface 332 is a convex surface. Theconcave surface 331 and convex surface 332 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 12 forvalues of the aspherical parameters.

The fourth lens element 340 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 341comprises a convex portion 3411 in the vicinity of the optical axis anda concave portion 3412 in the vicinity of the periphery of the fourthlens element 340. The image-side surface 342 has a concave portion 3421in the vicinity of the optical axis and a convex portion 3422 in thevicinity of a periphery of the fourth lens element 340. The object-sidesurface 341 and the image-side surface 342 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 12 forvalues of the aspherical parameters.

As illustrated in FIG. 13, it is clear that the optical imaging lens ofthe present embodiment may achieve great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) anddistortion aberration (d). Therefore, according to above illustration,the optical imaging lens of the present embodiment indeed achieves greatoptical performance, and the length of the optical imaging lens iseffectively shortened.

Reference is now made to FIGS. 14-17. FIG. 14 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a fourth exampleembodiment. FIG.15 shows an example table of optical data of each lenselement of the optical imaging lens according to the fourth exampleembodiment. FIG. 16 shows an example table of aspherical data of theoptical imaging lens according to the fourth example embodiment. FIG. 17shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe fourth example embodiment.

As shown in FIG. 14, the optical imaging lens of the present embodiment,in an order from an object side A1 to an image side A2, comprises anaperture stop 400, a first lens element 410, a second lens element 420,a third lens element 430 and a fourth lens element 440. Both of afiltering unit 450 and an image plane 460 of an image sensor may bepositioned at the image side A2 of the optical imaging lens 4. Each ofthe first, second, third, fourth lens elements 410, 420, 430, 440 andthe filtering unit 450 has an object-side surface 411/421/431/441/451facing toward the object side A1 and an image-side surface412/422/432/442/452 facing toward the image side A2. The aperture stop400, positioned in front of the first lens element 410, and togetherwith the first lens element 410 having positive refracting power couldeffectively shorten the length of the optical imaging lens 4. Here anexample embodiment of filtering unit 450 is an IR cut filter, which maybe positioned between the fourth lens element 440 and the image plane460. The filtering unit 450 filters light with specific wavelength fromthe light passing optical imaging lens 4. For example, IR light may befiltered, and this will prohibit the IR light which is not seen by humaneyes from producing an image on image plane 460.

Similarly, in the present embodiment, air gaps exist between the lenselements 410, 420, 430, 440, the filtering unit 450 and the image plane460 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the fourth embodiment and the first embodiment isthat the central thickness of lens T3 of the third lens element 430, theair gap G₃₄ between the third lens element 430 and the fourth lenselement 440 and the sum of all air gaps G_(aa) from the first lenselement 410 to the fourth lens element 440 are different. Please referto FIG. 15 for the optical characteristics of each lens elements in theoptical imaging lens 4 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=14.23;

(G _(aa) /T3)=1.02;

(EFL/G ₁₂)=20.87;

(T3/G ₁₂)=3.58;

(T2+T3)=0.83 (mm);

[(T2+T3)/T3]=1.87;

(G ₁₂ +G ₃₄)=0.15 (mm);

(f1+f3)=3.15 (mm);

(BFL/EFL)=0.5;

wherein the distance from the object-side surface 411 of the first lenselement 410 to the image plane 460 is 3.258 (mm), and the length of theoptical imaging lens 4 is shortened.

Example embodiments of the lens elements of the optical imaging lens 4may comprise the following example embodiments:

The first lens element 410 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 411 andthe image-side surface 412 are convex surfaces. The convex surfaces 411,412 may both be aspherical surfaces defined by the aspherical formula.Please refer to FIG. 16 for values of the aspherical parameters.

The second lens element 420 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 421and the image-side surface 422 are concave surfaces. The concavesurfaces 421, 422 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 16 for values of the asphericalparameters.

The third lens element 430 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 431 is aconcave surface and the image-side surface 432 is a convex surface. Theconcave surface 431 and the convex surface 432 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 16 forvalues of the aspherical parameters.

The fourth lens element 440 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 441comprises a convex portion 4411 in the vicinity of the optical axis anda concave portion 4412 in the vicinity of the periphery of the fourthlens element 440. The image-side surface 442 has a concave portion 4421in the vicinity of the optical axis and a convex portion 4422 in thevicinity of a periphery of the fourth lens element 440. The object-sidesurface 441 and the image-side surface 442 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 16 forvalues of the aspherical parameters.

As illustrated in FIG. 17, it is clear that the optical imaging lens ofthe present embodiment may achieve great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) anddistortion aberration (d). Therefore, according to above illustration,the optical imaging lens of the present embodiment indeed achieves greatoptical performance, and the length of the optical imaging lens iseffectively shortened.

Reference is now made to FIGS. 18-21. FIG. 18 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a fifth embodiment.FIG. 19 shows an example table of optical data of each lens element ofthe optical imaging lens according to the fifth example embodiment. FIG.20 shows an example table of aspherical data of the optical imaging lensaccording to the fifth example embodiment. FIG. 21 shows example chartsof longitudinal spherical aberration and other kinds of opticalaberrations of the optical imaging lens according to the fifth exampleembodiment.

As shown in FIG. 18, the optical imaging lens 5 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 500, a first lens element 510, a second lenselement 520, a third lens element 530 and a fourth lens element 540.Both of a filtering unit 550 and an image plane 560 of an image sensormay be positioned at the image side A2 of the optical imaging lens 5.Each of the first, second, third, fourth lens elements 510, 520, 530,540 and the filtering unit 550 has an object-side surface511/521/531/541/551 facing toward the object side A1 and an image-sidesurface 512/522/532/542/552 facing toward the image side A2. Theaperture stop 500, positioned in front of the first lens element 510,and together with the first lens element 510 having positive refractingpower could effectively shorten the length of the optical imaging lens5. Here an example embodiment of filtering unit 550 is an IR cut filter,which may be positioned between the fourth lens element 540 and theimage plane 560. The filtering unit 550 filters light with specificwavelength from the light passing optical imaging lens. For example, IRlight may be filtered, and this will prohibit the IR light which is notseen by human eyes from producing an image on image plane 560.

Similarly, in the present embodiment, air gaps exist between the lenselements 510, 520, 530, 540, the filtering unit 550 and the image plane560 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the fifth embodiments and the first embodimentsis that the central thickness of lens T3 of the third lens element 530,the air gap G₃₄ between the third lens element 530 and the fourth lenselement 540 and the sum of all air gaps G_(aa) from the first lenselement 510 to the fourth lens element 540 are different. Please referto FIG. 19 for the optical characteristics of each lens elements in theoptical imaging lens 5 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=4.86;

(G _(aa) /T3)=1.03;

(EFL/G ₁₂)=24.00;

(T3/G ₁₂)=4.73;

(T2+T3)=0.76 (mm);

[(T2+T3)/T3]=1.66;

(G ₁₂ +G ₃₄)=0.19 (mm);

(f1+f3)=3.12 (mm);

(BFL/EFL)=0.51;

wherein the distance from the object-side surface 511 of the first lenselement 510 to the image plane 560 is 3.081 (mm), and the length of theoptical imaging lens 5 is shortened.

Example embodiments of the lens elements of the optical imaging lens 5may comprise the following example embodiments:

The first lens element 510 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 511 andthe image-side surface 512 are convex surfaces. The convex surfaces 511,512 may both be aspherical surfaces defined by the aspherical formula.Please refer to FIG. 20 for values of the aspherical parameters.

The second lens element 520 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 521and an image-side surface 522 are concave surfaces. The concave surfaces521, 522 may both be aspherical surfaces defined by the asphericalformula. Please refer to FIG. 20 for values of the asphericalparameters.

The third lens element 530 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 531 is aconcave surface and the image-side surface 532 is a convex surface. Theconcave surface 531 and convex surface 532 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 20 forvalues of the aspherical parameters.

The fourth lens element 540 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 541comprises a convex portion 5411 in the vicinity of the optical axis anda concave portion 5412 in the vicinity of the periphery of the fourthlens element 540. The image-side surface 542 has a concave portion 5421in the vicinity of the optical axis and a convex portion 5422 in thevicinity of a periphery of the fourth lens element 540. The object-sidesurface 541 and surface 542 may both be aspherical surfaces defined bythe aspherical formula. Please refer to FIG. 20 for values of theaspherical parameters.

As illustrated in FIG. 21, it is clear that the optical imaging lens ofthe present embodiment may show great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) or distortionaberration (d). Therefore, according to above illustration, the opticalimaging lens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Reference is now made to FIGS. 22-25. FIG. 22 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a sixth exampleembodiment. FIG. 23 shows an example table of optical data of each lenselement of the optical imaging lens according to the sixth exampleembodiment. FIG. 24 shows an example table of aspherical data of theoptical imaging lens according to the sixth example embodiment. FIG. 25shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe sixth example embodiment.

As shown in FIG. 22, the optical imaging lens 6 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 600, a first lens element 610, a second lenselement 620, a third lens element 630 and a fourth lens element 640.Both of a filtering unit 650 and an image plane 660 of an image sensormay be positioned at the image side A2 of the optical imaging lens 6.Each of the first, second, third, fourth lens elements 610, 620, 630,640 and the filtering unit 650 has an object-side surface611/621/631/641/651 facing toward the object side A1 and an image-sidesurface 612/622/632/642/652 facing toward the image side A2. Theaperture stop 600, positioned in front of the first lens element 610,and together with the first lens element 610 having positive refractingpower could effectively shorten the length of the optical imaging lens6. Here an example embodiment of filtering unit 650 may be an IR cutfilter, which may be positioned between the fourth lens element 640 andthe image plane 660. The filtering unit 650 filters light with specificwavelength from the light passing optical imaging lens 6. For example,IR light may be filtered, and this may prohibit the IR light which isnot seen by human eyes from producing an image on image plane 660.

Similarly, in the present embodiment, air gaps exist between the lenselements 610, 620, 630, 640, the filtering unit 650 and the image plane660 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the sixth embodiments and the first embodimentsis that the central thickness of lens T3 of the third lens element 630,the air gap G₃₄ between the third lens element 630 and the fourth lenselement 640 and the sum of all air gaps G_(aa) from the first lenselement 610 to the fourth lens element 640 are different. Please referto FIG. 23 for the optical characteristics of each lens elements in theoptical imaging lens 6 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=4.07;

(G _(aa) /T3)=1.39;

(EFL/G ₁₂)=23.91;

(T3/G ₁₂)=3.59;

(T2+T3)=0.81 (mm);

[(T2+T3)/T3]=1.91;

(G ₁₂ +G ₃₄)=0.22 (mm);

(f1+f3)=3.97 (mm);

(BFL/EFL)=0.36;

wherein the distance from the object-side surface 611 of the first lenselement 610 to the image plane 660 is 3.24 (mm), and the length of theoptical imaging lens 6 is shortened.

Example embodiments of the lens elements of the optical imaging lens 6may comprise the following example embodiments:

The first lens element 610 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 611 andthe image-side surface 612 are convex surfaces. The convex surfaces 611and 612 may both be aspherical surfaces defined by the asphericalformula. Please refer to FIG. 24 for values of the asphericalparameters.

The second lens element 620 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 621and the image-side surface 622 are concave surfaces. The concavesurfaces 621, 622 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 24 for values of the asphericalparameters.

The third lens element 630 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 631 is aconcave surface and the image-side surface 632 is a convex surface. Theconcave surface 631 and convex surface 632 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 24 forvalues of the aspherical parameters.

The fourth lens element 640 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 641comprises a convex portion 6411 in the vicinity of the optical axis anda concave portion 6412 in the vicinity of the periphery of the fourthlens element 640. The image-side surface 642 has a concave portion 6421in the vicinity of the optical axis and a convex portion 6422 in thevicinity of a periphery of the fourth lens element 640. The object-sidesurface 641 and the image-side surface 642 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 24 forvalues of the aspherical parameters.

As illustrated in FIG. 25, it is clear that the optical imaging lens ofthe present embodiment may show great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) or distortionaberration (d). Therefore, according to above illustration, the opticalimaging lens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Reference is now made to FIGS. 26-29. FIG. 26 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a seventh exampleembodiment. FIG. 27 shows an example table of optical data of each lenselement of the optical imaging lens according to the seventh exampleembodiment. FIG. 28 shows an example table of aspherical data of theoptical imaging lens according to the seventh example embodiment. FIG.29 shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe seventh example embodiment.

As shown in FIG. 26, the optical imaging lens 7 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 700, a first lens element 710, a second lenselement 720, a third lens element 730 and a fourth lens element 740.Both of a filtering unit 750 and an image plane 760 of an image sensormay be positioned at the image side A2 of the optical imaging lens 7.Each of the first, second, third, fourth lens elements 710, 720, 730,740 and the filtering unit 750 has an object-side surface711/721/731/741/751 facing toward the object side A1 and an image-sidesurface 712/722/732/742/752 facing toward the image side A2. Theaperture stop 700, positioned in front of the first lens element 710,and together with the first lens element 710 having positive refractingpower could effectively shorten the length of the optical imaging lens7. Here an example embodiment of filtering unit 750 may comprise an IRcut filter, which is positioned between the fourth lens element 740 andthe image plane 760. The filtering unit 750 filters light with specificwavelength from the light passing optical imaging lens 7. For example,IR light is filtered, and this may prohibit the IR light which is notseen by human eyes from producing an image on image plane 760.

Similarly, in the present embodiment, air gaps exist between the lenselements 710, 720, 730, 740, the filtering unit 750 and the image plane760 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the seventh embodiments and the first embodimentsis that the central thickness of lens T3 of the third lens element 730,the air gap G₃₄ between the third lens element 730 and the fourth lenselement 740 and the sum of all air gaps G_(aa) from the first lenselement 710 to the fourth lens element 740 are different. Please referto FIG. 27 for the optical characteristics of each lens elements in theoptical imaging lens 7 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=4.15;

(G _(aa) /T3)=2.07;

(EFL/G ₁₂)=23.90;

(T3/G ₁₂)=2.72;

(T2+T3)=0.54 (mm);

[(T2+T3)/T3]=1.93;

(G ₁₂ +G ₃₄)=0.17 (mm);

(f1+f3)=3.34 (mm);

(BFL/EFL)=0.51;

wherein the distance from the object-side surface 711 of the first lenselement 710 to the image plane 760 is 3.064 (mm), and the length of theoptical imaging lens 7 is shortened.

Example embodiments of the lens elements of the optical imaging lens 7may comprise the following example embodiments:

The first lens element 710 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 711 andthe image-side surface 712 are convex surfaces. The convex surfaces 711and 712 may both be aspherical surfaces defined by the asphericalformula. Please refer to FIG. 28 for values of the asphericalparameters.

The second lens element 720 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 721 is aconvex surface. The image-side surface 722 has a concave portion 7221 inthe vicinity of the optical axis and a convex portion 7222 in thevicinity of a periphery of the second lens element 720. The convexsurface 721 and the image-side surface 722 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 28 forvalues of the aspherical parameters.

The third lens element 730 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 731 is aconcave surface and the image-side surface 732 is a convex surface. Theconcave surface 731 and convex surface 732 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 28 forvalues of the aspherical parameters.

The fourth lens element 740 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 741 is aconvex surface. The image-side surface 742 has a concave portion 7421 inthe vicinity of the optical axis and a convex portion 7422 in thevicinity of a periphery of the fourth lens element 740. The convexsurface 741 and the image-side surface 742 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 28 forvalues of the aspherical parameters.

As illustrated in FIG. 29, it is clear that the optical imaging lens ofthe present embodiment may show great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) or distortionaberration (d). Therefore, according to above illustration, the opticalimaging lens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Reference is now made to FIGS. 30-33. FIG. 30 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to an eighth exampleembodiment. FIG. 31 shows an example table of optical data of each lenselement of the optical imaging lens according to the eighth exampleembodiment. FIG. 32 shows an example table of aspherical data of theoptical imaging lens according to the eighth example embodiment. FIG. 33shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe eighth example embodiment.

As shown in FIG. 30, the optical imaging lens 8 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 800, a first lens element 810, a second lenselement 820, a third lens element 830 and a fourth lens element 840.Both of a filtering unit 850 and an image plane 860 of an image sensormay be positioned at the image side A2 of the optical imaging lens 8.Each of the first, second, third, fourth lens elements 810, 820, 830,840 and the filtering unit 850 has an object-side surface811/821/831/841/851 facing toward the object side A1 and an image-sidesurface 812/822/832/842/852 facing toward the image side A2. Theaperture stop 800, positioned in front of the first lens element 810,and together with the first lens element 810 having positive refractingpower could effectively shorten the length of the optical imaging lens8. Here an example embodiment of filtering unit 850 may comprise an IRcut filter, which is positioned between the fourth lens element 840 andthe image plane 860. The filtering unit 850 filters light with specificwavelength from the light passing optical imaging lens 8. For example,IR light is filtered, and this may prohibit the IR light which is notseen by human eyes from producing an image on image plane 860.

Similarly, in the present embodiment, air gaps exist between the lenselements 810, 820, 830, 840, the filtering unit 850 and the image plane860 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the eighth embodiments and the first embodimentsis that the central thickness of lens T3 of the third lens element 830,the air gap G₃₄ between the third lens element 830 and the fourth lenselement 840 and the sum of all air gaps G_(aa) from the first lenselement 810 to the fourth lens element 840 are different. Theobject-side surface 841 of the fourth lens element 840 facing toward theobject side A1 further comprises a convex portion 8412 in the vicinityof a periphery of the fourth lens element 840. Please refer to FIG. 31for the optical characteristics of each lens elements in the opticalimaging lens 8 of the present embodiment, wherein the values of therelations (1)˜(9) are:

(T3/G ₃₄)=11.72;

(G _(aa) /T3)=1.01;

(EFL/G ₁₂)=20.38;

(T3/G ₁₂)=4.11;

(T2+T3)=0.81 (mm);

[(T2+T3)/T3]=1.51;

(G ₁₂ +G ₃₄)=0.18 (mm);

(f1+f3)=2.50 (mm);

(BFL/EFL)=0.51;

wherein the distance from the object-side surface 811 of the first lenselement 810 to the image plane 860 is 3.408 (mm), and the length of theoptical imaging lens 8 is shortened.

Example embodiments of the lens elements of the optical imaging lens 8may comprise the following example embodiments:

The first lens element 810 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 811 andthe image-side surface 812 are convex surfaces. The convex surfaces 811and 812 may both be aspherical surfaces defined by the asphericalformula. Please refer to FIG. 32 for values of the asphericalparameters.

The second lens element 820 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface 821and the image-side surface 822 are concave surfaces. The concavesurfaces 821 and 822 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 32 for values of the asphericalparameters.

The third lens element 830 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 831 is aconcave surface and the image-side surface 832 is a convex surface. Theconcave surface 831 and convex surface 832 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 32 forvalues of the aspherical parameters.

The fourth lens element 840 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 841 hasa convex portion 8411 in the vicinity of the optical axis and a convexportion 8412 in the vicinity of a periphery of the fourth lens element840 and the image-side surface 842 has a concave portion 8421 in thevicinity of the optical axis and a convex portion 8422 in the vicinityof a periphery of the fourth lens element 840. The object-side surface841 and the image-side surface 842 may both be aspherical surfacesdefined by the aspherical formula. Please refer to FIG. 32 for values ofthe aspherical parameters.

As illustrated in FIG. 33, it is clear that the optical imaging lens ofthe present embodiment may show great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) or distortionaberration (d). Therefore, according to above illustration, the opticalimaging lens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Reference is now made to FIGS. 34-37. FIG. 34 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a ninth exampleembodiment. FIG. 35 shows an example table of optical data of each lenselement of the optical imaging lens according to the ninth exampleembodiment. FIG. 36 shows an example table of aspherical data of theoptical imaging lens according to the ninth example embodiment. FIG. 37shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe ninth example embodiment.

As shown in FIG. 34, the optical imaging lens 9 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 900, a first lens element 910, a second lenselement 920, a third lens element 930 and a fourth lens element 940.Both of a filtering unit 950 and an image plane 960 of an image sensormay be positioned at the image side A2 of the optical imaging lens 9.Each of the first, second, third, fourth lens elements 910, 920, 930,940 and the filtering unit 950 has an object-side surface911/921/931/941/951 facing toward the object side A1 and an image-sidesurface 912/922/932/942/952 facing toward the image side A2. Theaperture stop 900, positioned in front of the first lens element 910,and together with the first lens element 910 having positive refractingpower could effectively shorten the length of the optical imaging lens9. Here an example embodiment of filtering unit 950 may comprise an IRcut filter, which is positioned between the fourth lens element 940 andthe image plane 960. The filtering unit 950 filters light with specificwavelength from the light passing optical imaging lens 9. For example,IR light is filtered, and this may prohibit the IR light which is notseen by human eyes from producing an image on image plane 960.

Similarly, in the present embodiment, air gaps exist between the lenselements 910, 920, 930, 940, the filtering unit 950 and the image plane960 of the image sensor. Please refer to FIG. 1 for the positions of theair gaps. The sum of all air gaps d1, d2, d3 between the first andfourth lens elements is denoted by G_(aa).

One difference between the ninth embodiment and the first embodiment isthat the central thickness of lens T3 of the third lens element 930, theair gap G₃₄ between the third lens element 930 and the fourth lenselement 940 and the sum of all air gaps G_(aa) from the first lenselement 910 to the fourth lens element 940 are different. Theobject-side surface 921 of the second lens element 920 further comprisesa convex portion 9212 in the vicinity of a periphery of the second lenselement 920. Please refer to FIG. 35 for the optical characteristics ofeach lens elements in the optical imaging lens 9 of the presentembodiment, wherein the values of the relations (1)˜(9) are:

(T3/G ₃₄)=9.09;

(G _(aa) /T3)=1.02;

(EFL/G ₁₂)=23.90;

(T3/G ₁₂)=4.98;

(T2+T3)=0.59 (mm);

[(T2+T3)/T3]=1.79;

(G ₁₂ +G ₃₄)=0.10 (mm);

(f1+f3)=2.98 (mm);

(BFL/EFL)=0.51;

wherein the distance from the object-side surface 911 of the first lenselement 910 to the image plane 960 is 2.415 (mm), and the length of theoptical imaging lens 9 is shortened.

Example embodiments of the lens elements of the optical imaging lens 9may comprise the following example embodiments:

The first lens element 910 may have positive refracting power, which maybe constructed by plastic material. Both the object-side surface 911 andthe image-side surface 912 are convex surfaces. The convex surfaces 911and 912 may both be aspherical surfaces defined by the asphericalformula. Please refer to FIG. 36 for values of the asphericalparameters.

The second lens element 920 may have negative refracting power, whichmay be constructed by plastic material. The image-side surface 922 is aconcave surface. The object-side surface 921 has a concave portion 9211in the vicinity of the optical axis and a convex portion 9212 in thevicinity of a periphery of the second lens element 920. The object-sidesurface 921 and image-side surface 922 may both be aspherical surfacesdefined by the aspherical formula. Please refer to FIG. 36 for values ofthe aspherical parameters.

The third lens element 930 may have positive refracting power, which maybe constructed by plastic material. The object-side surface 931 is aconcave surface and the image-side surface 932 is a convex surface. Theconcave surface 931 and convex surface 932 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 36 forvalues of the aspherical parameters.

The fourth lens element 940 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 941 is aconvex surface. The image-side surface 942 has a concave portion 9421 inthe vicinity of the optical axis and a convex portion 9422 in thevicinity of a periphery of the fourth lens element 940. The convexsurface 941 and image-side surface 942 may both be aspherical surfacesdefined by the aspherical formula. Please refer to FIG. 36 for values ofthe aspherical parameters.

As illustrated in FIG. 37, it is clear that the optical imaging lens ofthe present embodiment may show great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) or distortionaberration (d). Therefore, according to above illustration, the opticalimaging lens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Reference is now made to FIGS. 38-41. FIG. 38 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a tenth exampleembodiment. FIG. 39 shows an example table of optical data of each lenselement of the optical imaging lens according to the tenth exampleembodiment. FIG. 40 shows an example table of aspherical data of theoptical imaging lens according to the tenth example embodiment. FIG. 41shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe tenth example embodiment.

As shown in FIG. 38, the optical imaging lens 10 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 1000, a first lens element 1010, a secondlens element 1020, a third lens element 1030 and a fourth lens element1040. Both of a filtering unit 1050 and an image plane 1060 of an imagesensor may be positioned at the image side A2 of the optical imaginglens 10. Each of the first, second, third, fourth lens elements 1010,1020, 1030, 1040 and the filtering unit 1050 has an object-side surface1011/1021/1031/1041/1051 facing toward the object side A1 and animage-side surface 1012/1022/1032/1042/1052 facing toward the image sideA2. The aperture stop 1000, positioned in front of the first lenselement 1010, and together with the first lens element 1010 havingpositive refracting power could effectively shorten the length of theoptical imaging lens 10. Here an example embodiment of filtering unit1050 may comprise an IR cut filter, which is positioned between thefourth lens element 1040 and the image plane 1060. The filtering unit1050 filters light with specific wavelength from the light passingoptical imaging lens 10. For example, IR light is filtered, and this mayprohibit the IR light which is not seen by human eyes from producing animage on image plane 1060.

Similarly, in the present embodiment, air gaps exist between the lenselements 1010, 1020, 1030, 1040, the filtering unit 1050 and the imageplane 1060 of the image sensor. Please refer to FIG. 1 for the positionsof the air gaps. The sum of all air gaps d1, d2, d3 between the firstand fourth lens elements is denoted by G_(aa).

One difference between the tenth embodiments and the first embodimentsis that the central thickness of lens T3 of the third lens element 1030,the air gap G₃₄ between the third lens element 1030 and the fourth lenselement 1040 and the sum of all air gaps G_(aa) from the first lenselement 1010 to the fourth lens element 1040 are different. Please referto FIG. 39 for the optical characteristics of each lens elements in theoptical imaging lens 10 of the present embodiment, wherein the values ofthe relations (1)˜(9) are:

(T3/G ₃₄)=4.62;

(G _(aa) /T3)=1.36;

(EFL/G ₁₂)=23.48;

(T3/G ₁₂)=3.42;

(T2+T3)=0.93 (mm);

[(T2+T3)/T3]=2.31;

(G ₁₂ +G ₃₄)=0.21 (mm);

(f1+f3)=3.06 (mm);

(BFL/EFL)=0.31;

wherein the distance from the object-side surface 1011 of the first lenselement 1010 to the image plane 1060 is 3.16 (mm), and the length of theoptical imaging lens 10 is shortened.

Example embodiments of the lens elements of the optical imaging lens 10may comprise the following example embodiments:

The first lens element 1010 may have positive refracting power, whichmay be constructed by plastic material. Both the object-side surface1011 and the image-side surface 1012 are convex surfaces. The convexsurfaces 1011 and 1012 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 40 for values of the asphericalparameters.

The second lens element 1020 may have negative refracting power, whichmay be constructed by plastic material. Both the object-side surface1021 and the image-side surface 1022 are concave surfaces. The concavesurfaces 1021, 1022 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 40 for values of the asphericalparameters.

The third lens element 1030 may have positive refracting power, whichmay be constructed by plastic material. The object-side surface 1031 isa concave surface and the image-side surface 1032 is a convex surface.The concave surface 1031 and convex surface 1032 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 40 forvalues of the aspherical parameters.

The fourth lens element 1040 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 1041comprises a concave portion 10411 in the vicinity of the optical axisand a concave portion 10412 in the vicinity of the periphery of thefourth lens element 1040. The image-side surface 1042 has a concaveportion 10421 in the vicinity of the optical axis and a convex portion10422 in the vicinity of a periphery of the fourth lens element 1040.The object-side surface 1041 and the image-side surface 1042 may both beaspherical surfaces defined by the aspherical formula. Please refer toFIG. 40 for values of the aspherical parameters.

As illustrated in FIG. 41, it is clear that the optical imaging lens ofthe present embodiment may show great characteristics in longitudinalspherical aberration (a), astigmatism in the sagittal direction (b),astigmatism in the tangential direction (c) or distortion aberration(d). Therefore, according to above illustration, the optical imaginglens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Reference is now made to FIGS. 42-45. FIG. 42 illustrates an examplecross-sectional view of an optical imaging lens having four lenselements of the optical imaging lens according to a eleventh exampleembodiment. FIG. 43 shows an example table of optical data of each lenselement of the optical imaging lens according to the eleventh exampleembodiment. FIG. 44 shows an example table of aspherical data of theoptical imaging lens according to the eleventh example embodiment. FIG.45 shows example charts of longitudinal spherical aberration and otherkinds of optical aberrations of the optical imaging lens according tothe eleventh example embodiment.

As shown in FIG. 42, the optical imaging lens 11 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises a first lens element 1110, an aperture stop 1100, a secondlens element 1120, a third lens element 1130 and a fourth lens element1140. Both of a filtering unit 1150 and an image plane 1160 of an imagesensor may be positioned at the image side A2 of the optical imaginglens 11. Each of the first, second, third, fourth lens elements 1110,1120, 1130, 1140 and the filtering unit 1150 has an object-side surface1111/1121/1131/1141/1151 facing toward the object side A1 and animage-side surface 1112/1122/1132/1142/1152 facing toward the image sideA2. Here an example embodiment of filtering unit 1150 may comprise an IRcut filter, which is positioned between the fourth lens element 1140 andthe image plane 1160. The filtering unit 1150 filters light withspecific wavelength from the light passing optical imaging lens 11. Forexample, IR light is filtered, and this may prohibit the IR light whichis not seen by human eyes from producing an image on image plane 1160.

Similarly, in the present embodiment, air gaps exist between the lenselements 1110, 1120, 1130, 1140, the filtering unit 1150 and the imageplane 1160 of the image sensor. Please refer to FIG. 1 for the positionsof the air gaps. The sum of all air gaps d1, d2, d3 between the firstand fourth lens elements is denoted by G_(aa).

One difference between the eleventh embodiments and the firstembodiments is that the central thickness of lens T3 of the third lenselement 1130, the air gap G₃₄ between the third lens element 1130 andthe fourth lens element 1140 and the sum of all air gaps G_(aa) from thefirst lens element 1110 to the fourth lens element 1140 are different.The aperture stop is positioned between the first lens element 1110 andthe second lens element 1120. Please refer to FIG. 43 for the opticalcharacteristics of each lens elements in the optical imaging lens 11 ofthe present embodiment, wherein the values of the relations (1)˜(9) are:

(T3/G ₃₄)=4.29;

(G _(aa) /T3)=2.33;

(EFL/G ₁₂)=23.85;

(T3/G ₁₂)=3.62;

(T2+T3)=0.75 (mm);

[(T2+T3)/T3]=1.55;

(G ₁₂ +G ₃₄)=0.25 (mm);

(f1+f3)=3.76 (mm);

(BFL/EFL)=0.33;

wherein the distance from the object-side surface 1111 of the first lenselement 1110 to the image plane 1160 is 3.818 (mm), and the length ofthe optical imaging lens 11 is shortened.

Example embodiments of the lens elements of the optical imaging lens 11may comprise the following example embodiments:

The first lens element 1110 may have positive refracting power, whichmay be constructed by plastic material. Both the object-side surface1111 and the image-side surface 1112 are convex surfaces. The convexsurfaces 1111 and 1112 may both be aspherical surfaces defined by theaspherical formula. Please refer to FIG. 44 for values of the asphericalparameters.

The second lens element 1120 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 1121comprises a concave portion 11211 in the vicinity of the optical axisand a convex portion 11212 in the vicinity of the periphery of thesecond lens element 1120. The image-side surface 1122 is a concavesurface. The object-side surface 1121 and the image-side surface 1122may both be aspherical surfaces defined by the aspherical formula.Please refer to FIG. 44 for values of the aspherical parameters.

The third lens element 1130 may have positive refracting power, whichmay be constructed by plastic material. The object-side surface 1131 isa concave surface and the image-side surface 1132 is a convex surface.The concave surface 1131 and convex surface 1132 may both be asphericalsurfaces defined by the aspherical formula. Please refer to FIG. 44 forvalues of the aspherical parameters.

The fourth lens element 1140 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 1141comprises a convex portion 11411 in the vicinity of the optical axis anda concave portion 11412 in the vicinity of the periphery of the fourthlens element 1140. The image-side surface 1142 has a concave portion11421 in the vicinity of the optical axis and a convex portion 11422 inthe vicinity of a periphery of the fourth lens element 1140. Theobject-side surface 1141 and the image-side surface 1142 may both beaspherical surfaces defined by the aspherical formula. Please refer toFIG. 44 for values of the aspherical parameters.

As illustrated in FIG. 45, it is clear that the optical imaging lens ofthe present embodiment may show great optical characteristics inlongitudinal spherical aberration (a), astigmatism in the sagittaldirection (b), astigmatism in the tangential direction (c) or distortionaberration (d). Therefore, according to above illustration, the opticalimaging lens of the present embodiment indeed achieves great opticalperformance, and the length of the optical imaging lens is effectivelyshortened.

Please refer to FIG. 46, which shows the values of (T3/G₃₄),(G_(aa)/T3), (EFL/G₁₂), (T3/G₁₂), (T2+T3), [(T2+T3)/T3], (G₁₂+G₃₄),(f1+f3), (BFL/EFL) and fno of all eleven embodiments.

Reference is now made to FIG. 47, which illustrates an examplestructural view of an example embodiment of mobile device 20 applying anaforesaid optical imaging lens. The mobile device 20 comprises a housing210 and an optical imaging lens assembly 220 positioned in the housing210. An example of the mobile device 20 may be, but is not limited to, amobile phone.

As shown in FIG. 47, the optical imaging lens assembly 220 may comprisean aforesaid optical imaging lens, for example the optical imaging lens1 of the first embodiment, a lens barrel 230 for positioning the opticalimaging lens 1, a module housing unit 240 for positioning the lensbarrel 230 and an image sensor 161 which is positioned at an image sideof the optical imaging lens 1. The image plane 160 is formed on theimage sensor 161.

In some other example embodiments, the structure of the filtering unit150 may be omitted. In some example embodiments, the housing 210, thelens barrel 230, and/or the module housing unit 240 may be integratedinto a single component or assembled by multiple components. In someexample embodiments, the image sensor 161 used in the present embodimentis directly attached to the substrate 162 in the form of a chip on board(COB) package, and such package is different from traditional chip scalepackages (CSP) since COB package does not require a cover glass beforethe image sensor 161 in the optical imaging lens 1.

Aforesaid exemplary embodiments are not limited to this package type andcould be selectively incorporated in other described embodiments.

The module housing unit 240 comprises a lens backseat 2401 and an imagesensor base 2402 positioned between the lens backseat 2401 and the imagesensor 161. The lens barrel 230 and the lens backseat 2401 arepositioned along a same axis, and the lens barrel 230 is positionedinside the lens backseat 2401.

Because the length of the optical imaging lens 1 is merely 3.063 (mm),the size of the mobile device 20 may be quite small. Therefore, theembodiments described herein meet the market demand for smaller sizedproduct designs.

Reference is now made to FIG. 48, which shows another structural view ofan example embodiment of mobile device 22 applying the aforesaid opticalimaging lens 1. One difference between the mobile device 22 and themobile device 20 may be the module housing unit 240 further comprisingan autofocus module 2403. The autofocus module 2403 may comprise a lensseat 2404, a lens backseat 2401, a coil 2405 and a magnetic unit 2406.The lens seat 2404, which is close to the outside of the lens barrel230, and the lens barrel 230 are positioned along an axis II′, and thelens backseat 2401 is positioned along with the axis II′ and around theoutside of the lens seat 2404. The coil 2405 is positioned between thelens seat 2404 and the inside of the lens backseat 2401. The magneticunit 2406 is positioned between the outside of the coil 2405 and theinside of the lens backseat 2401.

The lens barrel 230 and the optical imaging lens 1 positioned thereinare driven by the lens seat 2404 for moving along the axis II′. Thesensor backseat 2402 is close to the lens backseat 2401. The filteringunit 150, for example IR cut, is positioned on the sensor backseat 2402.The rest structure of the mobile device 22 is similar to the mobiledevice 1.

Similarly, because the length of the optical imaging lens 1, 3.063 (mm),is shortened, the mobile device 22 may be designed with a smaller sizeand meanwhile good optical performance is still provided. Therefore, thepresent embodiment meets the demand of small sized product design andthe request of the market.

According to above illustration, it is clear that the mobile device andthe optical imaging lens thereof in example embodiments, throughcontrolling ratio of at least one central thickness of lens element toan air gap along the optical axis between two lens elements and theratio of a sum of all air gaps along the optical axis between four lenselements to a central thickness of lens in a predetermined range, andincorporated with detail structure and/or reflection power of the lenselements, the length of the optical imaging lens is effectivelyshortened and meanwhile good optical characters are still provided.

While various embodiments in accordance with the disclosed principleshave been described above, it should be understood that they have beenpresented by way of example only, and are not limiting. Thus, thebreadth and scope of exemplary embodiment(s) should not be limited byany of the above-described embodiments, but should be defined only inaccordance with the claims and their equivalents issuing from thisdisclosure. Furthermore, the above advantages and features are providedin described embodiments, but shall not limit the application of suchissued claims to processes and structures accomplishing any or all ofthe above advantages.

Additionally, the section headings herein are provided for consistencywith the suggestions under 37 C.F.R. 1.77 or otherwise to provideorganizational cues. These headings shall not limit or characterize theinvention(s) set out in any claims that may issue from this disclosure.Specifically, a description of a technology in the “Background” is notto be construed as an admission that technology is prior art to anyinvention(s) in this disclosure. Furthermore, any reference in thisdisclosure to “invention” in the singular should not be used to arguethat there is only a single point of novelty in this disclosure.Multiple inventions may be set forth according to the limitations of themultiple claims issuing from this disclosure, and such claimsaccordingly define the invention(s), and their equivalents, that areprotected thereby. In all instances, the scope of such claims shall beconsidered on their own merits in light of this disclosure, but shouldnot be constrained by the headings herein.

What is claimed is:
 1. An optical imaging lens, in an order from anobject side to an image side, comprising first, second, third and fourthlens elements, each of said first, second, third, and fourth lenselements having an object-side surface facing toward the object side andan image-side surface facing toward the image side, wherein: said firstlens element with positive refracting power, and said object-sidesurface thereof being a convex surface; said second lens element withnegative refracting power, said object-side surface thereof comprising aconcave portion in the vicinity of the optical axis and said image-sidesurface comprising a concave portion in the vicinity of the periphery ofsaid second lens element; said third lens element with positiverefracting power, said object-side surface thereof being a concavesurface and said image-side surface thereof being a convex surface; saidobject-side surface of said fourth lens element comprising a convexportion in the vicinity of the optical axis and said image-side surfaceof said fourth lens element comprising a concave portion in the vicinityof the optical axis and a convex portion in the vicinity of a peripheryof the fourth lens element; lens as a whole having only the four lenselements with refracting power, wherein a central thickness of the thirdlens element along the optical axis is T3, an air gap between the thirdlens element and the fourth lens element along the optical axis is G₃₄,and a sum of all air gaps between the first lens element and the fourthlens element along the optical axis is G_(aa), and T3, G₃₄, and G_(aa)satisfy the relations:(T3/G ₃₄)>4; and(G _(aa) /T3)>1.
 2. The optical imaging lens according to claim 1,wherein the first lens element further comprises a image-side surfacefacing toward the image side, the image-side surface comprising a convexportion in the vicinity of a periphery of the first lens element.
 3. Theoptical imaging lens according to claim 2, wherein an air gap betweenthe first lens element and the second lens element along the opticalaxis is G₁₂, an effective focal length is EFL, and EFL and G₁₂ satisfythe relation:(EFL/G ₁₂)<24.
 4. The optical imaging lens according to claim 3, whereinG₁₂ and T3 satisfy the relation:(T3/G ₁₂)<5.
 5. The optical imaging lens according to claim 4, wherein acentral thickness of the second lens element along the optical axis isT2, and T2 and T3 satisfy the relation:0.5≦(T2+T3)≦0.83 (mm).
 6. The optical imaging lens according to claim 5,further comprising an aperture stop positioned in front of the firstlens element.
 7. The optical imaging lens according to claim 6, whereinT2 and T3 satisfy the relation:1.5<[(T2+T3)/T3]<2.5.
 8. The optical imaging lens according to claim 7,wherein G₁₂ and G₃₄ satisfy the relation:0.07<(G ₁₂ +G ₃₄)<0.25 (mm).
 9. The optical imaging lens according toclaim 8, wherein a focal length of the first lens element is f1, and afocal length of the third lens element is f3, and f1 and f3 satisfy therelation:2<(f1+f3)<4 (mm).
 10. The optical imaging lens according to claim 7,wherein a back focal length of the optical imaging lens, defined as thedistance between the image-side surface of the fourth lens element andan image plane along the optical axis, is BFL, and BFL and EFL satisfythe relation:(BFL/EFL)≧0.5.
 11. The optical imaging lens according to claim 5,further comprising an aperture stop positioned between the first lenselement and the second lens element.
 12. The optical imaging lensaccording to claim 3, wherein a central thickness of the second lenselement along the optical axis is T2, and T2 and T3 satisfy therelation:0.5≦(T2+T3)≦0.83 (mm).
 13. The optical imaging lens according to claim3, further comprising an aperture stop positioned in front of the firstlens element.
 14. The optical imaging lens according to claim 3, whereina central thickness of the second lens element along the optical axis isT2, and T2 and T3 satisfy the relation:1.5<[(T2+T3)/T3]<2.5.
 15. The optical imaging lens according to claim 3,wherein G₁₂ and G₃₄ satisfy the relation:0.07<(G ₁₂ +G ₃₄)<0.25 (mm).
 16. The optical imaging lens according toclaim 3, wherein a focal length of the first lens element is f1, and afocal length of the third lens element is f3, and f1 and f3 satisfy therelation:2<(f1+f3)<4 (mm).
 17. The optical imaging lens according to claim 3,wherein a back focal length of the optical imaging lens, defined as thedistance between the image-side surface of the fourth lens element andan image plane along the optical axis, is BFL, and BFL and EFL satisfythe relation:(BFL/EFL)≧0.5.
 18. A mobile device, comprising: a housing; and anoptical imaging lens assembly positioned in the housing and comprising:a lens barrel; the optical imaging lens as claimed in claim 1,positioned in the barrel; a module housing unit for positioning the lensbarrel; and an image sensor positioned at the image-side of the opticalimaging lens.
 19. The mobile device according to claim 18, wherein themodule housing unit further comprises an autofocus module comprising alens seat and a lens backseat, the lens seat is positioned close to theoutside of the lens barrel and along with an axis, the lens backseat ispositioned along the axis and around the outside of the lens seat, andthe lens barrel and the optical imaging lens positioned therein aredriven by the lens seat for moving along the axis to control thefocusing of the optical imaging lens.
 20. The mobile device according toclaim 19, wherein the module housing unit further comprises an imagesensor base positioned between the lens backseat and the image sensor,and the image sensor base is closed to the lens backseat.